Creating a new 20g reef from 55g, still need to cycle?

[h2o]

this coming weekend i will transfer live sand, some live rocks, and all water from my 55g (after water change) into a new 20g. i will also add a bag of nature's ocean. Since all the stuff from 55g are well established, should i still need to follow the cycling rule? i know about the always test water rules but just want to hear your opinion.
The 20g will have 2x55watt retro fit pc. i plan to start lighting the tank few hours a day and gradually increase. and it should have estimated 3" sand bed. would like to add a pair of cardinal soon too.

 

[byrself]

i think there's a chance you could have some flucuations in some of your water parameters so i'd try to set it up and let it run as long as you can before you add the goodies. there's some beneficial stuff that grows on the walls of the tank so you are gonna lose some of those with the new tank. it's gonna settle alot quicker than an all new tank but you still should be cautious and have a back up plan if you can.
just my opinion, good luck

 

[nm reef]

I would still approach it as if it were a new system...even with the water/LR/LS from the established system. You may not have any cycle to speak of....still I would let it settle and check the ammonia/nitrite/nitrate as if it were new. Let it stabalise prior to adding any livestock.......sounds like a well thought out plan...hope it goes well.